Biggest shoes to fill: North Carolina

Our series continues today with the Tar Heels, who, coincidentally, kick off spring practice this afternoon. While UNC is not without its challenges in light of this week's NCAA penalties, its biggest challenge on the field will be replacing a dominant pass-rusher.

OUT: Quinton Coples. One of the top defensive end prospects and a potential top-10 pick in this year's NFL draft, Coples led North Carolina in both tackles for loss and sacks last season, notching 15.5 and 7.5, respectively, despite facing plenty of double-teams. His 55 tackles were fourth-most on the Tar Heels. Coples will leave quite a void after a college career that featured 144 total tackles, 22 sacks, five forced fumbles, 22 quarterback hurries and four pass break-ups.

IN: Kareem Martin. Starting all 13 games in 2011, Martin was tied for third on the Tar Heels last season with seven tackles for loss. He added four sacks, five quarterback hurries, a fumble recovery and 40 total tackles. For his career, the junior-to-be has 56 total tackles, 8.5 tackles for loss, seven hurries and seven pass breakups. One of the most decorated prospects in the state of North Carolina coming out of Roanoke Rapids High School, Martin started the first three games of his college career in 2010. He'll look to take the next step in 2012.